After a hundred trillion plus calculations(348 checks ~ 1.7 trillion * 80 calculations per check) I was able to find even better results. The theoretical maximum minimum spread is ~85 digital levels. With using only 34 resistor values ( I could have used many more values say 40 or 50 but I feel that the result would have been similar and took another day or more to calculate I was able to find 2 results with a minimum spread of ~78 digital levels. The resistor values are:

1) 390 3900 9100 510 5100 8200 2700 39

2) 390 3900 9100 560 5100 8200 2700 39

you can multiply these values by 10 or 100 and get the same result. The 34 resistor values I used were as follows:

SparkFun is an online retail store that sells the bits and pieces to
make your electronics projects possible. Whether it's a robot that can
cook your breakfast or a GPS cat tracking device, our products and
resources are designed to make the world of electronics more accessible.

In addition to products, SparkFun also offers
classes and online tutorials to help educate
individuals in the wonderful world of embedded electronics.